Abstract Socioeconomic status (SES) is a fundamental contributor to health and disease across the life course. Inequalities in health that disfavor sexual and gender minorities have been widely documented in both adolescence and adulthood. Despite the importance of SES to health, knowledge about factors that pattern these resources and strains across sexual and gender minority groups is incomplete, largely because of the absence of appropriate and high quality data, as well as study design limitations for data that do exist. In synchrony with the National Longitudinal Study of Adolescent to Adult Health (Add Health) Wave V program project design and activity, this proposed ancillary project will collect, clean, disseminate, and analyze new data from a subset of the Add Health cohort (sexual minorities, transgendered individuals, and a comparison sample of heterosexuals) via a theory-guided ancillary survey that will add information about formative experiences more specific to sexual orientation and gender development, and enhance existing prospective information about SES and determinants of SES. Based on Wave IV data we plan to recruit approximately 2,200 self-identified sexual/gender minorities and a random comparison sample of 1,500 heterosexuals. The unique data collected via this project will provide an unprecedented opportunity for new and current Add Health users to prospectively study the intersections of sexual orientation, gender identity, socioeconomic factors, and health in a population-based sample across the life course at only marginal cost. Positioned within a life course framework and guided by Minority Stress Theory, we will also address three substantive analytical aims using the released ancillary data: 1) to describe the timing and sequence of theoretical milestones in the development of sexual orientation and gender identity; 2) to examine potential mediators (i.e., parent-child relationship quality and subsequent adolescent educational attainment and housing status) of the association between sexual orientation, gender identity, and young adult SES; and 3) to test a hypothesized pathway that economic strain heightens stress, which in turn elevates depressive symptoms. Findings made possible through these new data, in combination with existing longitudinal information about Add Health sample members, have the potential for critical impact on public health policy and intervention strategies to reduce the prevalence of and disparities in disease burden for the sexual and gender minority population.